Brushless motors are widely used instead of brushed motors; for example, JP Laid-open Application No. 2007-20588 teaches that they are used in grass-mowers having a power-driven rotary cutter.
Another example is shown by JP Patent No. 3673923 which discloses a power-driven roller-conveyor and a power-driven winder for winding up a long object, such as paper, film or cloth. The roller conveyor must transport the cartons constantly kept upright to the delivery port, and the winder must roll up a long object constantly in a stretched manner.
However, the problem tends to arise from the inertia involved in the stoppage of the motor. The inertia is likely to loosen the fasteners in the rotary cutter, thereby releasing the rotary cutter from the body of the grass mower. This is very dangerous for the operator and people nearby. The same trouble occurs in the roller conveyor in that the cartons placed on the rollers fall down on the floor, thereby damaging the contents of the cartons. In the case of the winder the tensioned object detrimentally becomes loose.
Therefore, in those apparatus using rotary members such as rotary cutters and rollers it is required to stop the motors gradually so as to minimize the inertia.
The present invention is directed to solve the problems discussed above, and is to provide a brake-controllable brushless motor adapted for use in the apparatus having a power-driven rotary member.